I am a PhD graduate from a good US university and my field is related to water resources and environment. I did my MS in Water Reousrces Engineering and BE in Civil Engineering from foreign universities. 

I am currently on OPT and working as a postdoctoral researcher. I have 4 peer-reviewed journal publications (all are in good journals), 6 citations (excluding myself) and 15 conference presentations, and couple of project reports published (at least one is peer-reviewed). I have reviewed other scientist's work 11 times from 4 different journals. I am seriously considering for EB2 NIW. As I have quite a few citations, I am debating whether I apply for EB-2 NIW or not. 

I am looking for suggestions and would be grateful if you could share your EB2 NIW approval experience in the field of water resources, environmental, civil/environmental engineering. 

In addition, if you have "Do It Yourself" kit or approved sample ecommendation/pettion letters, would you mind sharing to me (rajenpl@yahoo.com).

Thanks for your time and considertaion.

It depends how you write the cover letter. I have seen somebody's EB2 NIW application successful with two papers (total less than 10 citations) plus few conference presentations only.